The present invention relates to a high-quality titanium target for sputtering, which is free from the generation of fractures and cracks during high-power sputtering (high-rate sputtering) and capable of stabilizing the sputtering characteristics.
The impurity concentration described in the present specification will be displayed in mass parts per million (mass ppm) in all cases.
In recent years, various electronic devices have been devised beginning with the breakthrough of semiconductors, and the improvement of the performance thereof as well as the development of new devices are being sought on a daily basis.
Under these circumstances, there is a tendency to miniaturization of electronic devices and equipment and to increase in the degree of integration thereof. Numerous thin films are formed during the manufacturing process of many of such devices and equipment, and titanium, from its unique metallic property, is used in the formation of thin films of various electronic devices as a titanium or its alloy film, a titanium silicide film, a titanium nitride film, or the like.
Generally speaking, the aforementioned films such as a titanium or its alloy film, a titanium silicide film and a titanium nitride film can be formed with a physical deposition method such as sputtering or vacuum deposition. Explained below is the sputtering method which is used most comprehensively among the above.
This sputtering method is a method of physically colliding positive ions such as Ar+ to a target disposed on a cathode and discharging the metal atoms configuring the target with the collision energy thereof. Nitrides can be formed by using titanium or its alloy (TiAl alloy, etc.) as the target and conducting sputtering under a mixed gas atmosphere of argon gas and nitrogen.
In recent years, in order to improve the production efficiency, there are demands for high-rate sputtering (high-power sputtering). Here, there are cases where the target is subject to fractures or cracks, and these problems tend to prevent stable sputtering. Patent Document 1 and Patent Document 2 listed below are cited as prior art documents.
[Patent Document 1] International Publication No. WO01/038598
[Patent Document 2] Published Japanese Translation No. 2001-509548 of PCT Application